What is it?
The Body Fat Calculator estimates what percentage of your body is fat, using only a measuring tape. It uses the U.S. Navy method, which is usually within 3–4% of a lab scan, and also shows your fat and lean mass if you add your weight.
Who is it for?
Fitness enthusiasts tracking progress, people losing weight who want to see fat loss rather than scale weight, and trainers.
How to use it
Choose your Sex and enter Height, Neck, Waist (at the navel), and for women Hips (widest point). Weight (optional) adds fat and lean mass. The answer appears as you type; there is no Calculate button. Tap Copy result to copy it, or Share on WhatsApp to send it.
Measuring correctly
- Use a soft tape, snug on the skin but not pressing in, in the morning before eating.
- Neck: just below the Adam’s apple, tape sloping slightly down at the front.
- Waist: at the navel, relaxed, after breathing out. Don’t suck in.
- Hips: the widest part of the buttocks.
- Measure twice and use the average. One centimetre off at the waist changes the result by about 1%.
Typical ranges
- Men: fitness 14–17%, average 18–24%, high 25%+.
- Women: fitness 21–24%, average 25–31%, high 32%+.
Track the trend over months rather than one reading.
This is general information to help you understand your numbers, not medical advice. Talk to a doctor about your own health.
Errors and how to fix them
- “Waist must be bigger than neck”: re-measure; the waist is at the navel.
- “Check the measurements”: a value is missing or unrealistic (often hips missing for women).
Open the tool: Body Fat Calculator
Still stuck?
Contact support. Tell us which tool or page you were using, what you tapped, what you saw, and your phone or computer and browser (for example: Android phone, Chrome). We reply by email.
Questions, or an error not listed here?
Tell us in the comments: what you were doing, the exact message you saw, and your device and browser. We read every comment and add new fixes to this article.